Question: How many significant figures does $0240$ have?
Answer: Identify the non-zero digits and any zeros between them. These are all significant. $0{24}0$ Leading zeros are not significant. $\color{orange}{0}{24}0$ Since there is no decimal, trailing zeros are not significant. $\color{orange}{0}{24}\color{orange}{0}$ Counting all the significant digits gives us 2.